Evaluation of TANESCO revenue losses due to network power quality disturbances

Poor power quality supplied by TANESCO to its customers is manifested by complaints arising from customers looking for compensation for their damaged properties, cost of stoppage of manufacturing processes and cost of down time. On the other hand utility company itself is suffering from revenue losses, damaged network equipments and unreliability of power supply. In this study, evaluation of utility revenue losses is made possible by applying basic computation procedures such as evaluation of average consumed energy (kWh), evaluation of calculated average consumed energy from installed load capacity, evaluation of energy losses (energy difference) and hence loss factor (k) of every customer from TANESCO monthly charged bills. Power quality recorder instruments fixed at grid substations of the utility network are utilized for indication and justification of the existing problem. These power quality recorders provide detailed information with regard to network disturbances. The captured information is downloaded either remotely or locally by a Laptop Computer which has special software, called Power Quality Recorder Manager (PQRM). Results obtained from this study shows that the estimated utility revenue loss due to unsold energy caused by disturbances in the supply network for the period January 2007 to December 2009 is 25.9 % of the total utility revenue income. Accordingly, the estimated utility revenue loss for the three years under study is approximately Tshs 363 billion. The results illustrate that power quality disturbances have a direct impact on energy sales. Accordingly, recommendations are given on scientific approaches in dealing with and minimizing disturbances in the power network.